1. Field of the Invention
The invention relates to polymeric organotin hydrides useful as reducing agents and also to a process for reducing organic compounds using such polymeric organotin hydrides.
2. Description of the Prior Art
Polymers containing tin or other metals in their molecule are known. See, for example, U.S. Pat. Nos. 3,223,686; 3,190,901; and 3,684,752. However, no prior art is known which discloses organic polymers containing organotin hydride functions pendant from main polymer chains. The above-noted U.S. Pat. No. 3,223,686 of Natta et al discloses alkyl tin-containing vinyl monomers [e.g., 5-(trimethylstannyl)pentene-1] which are polymerizable with a transition metal catalyst to high molecular weight, linear, regular non-hydride polymers. The resulting polymer products are disclosed as useful as structural polymers in applications requiring high melting point, high temperature stability, and relatively low flammability.
The use of metal hydrides generally for reducing, e.g., carbonyl compounds to corresponding carbinols, is known. Tin hydrides are among the metal hydrides known to have reducing activity. They are especially attractive in certain applications since they selectively reduce organohalides to hydrocarbons in the presence of ketones, amides, nitriles, etc., which are reduced substantially more slowly. However, a disadvantage of tin hydrides used heretofore is that the tin hydrides are soluble in many desirable organic reaction media and thus it is sometimes difficult to remove them from the reduced compound, thereby lowering the efficiency of the method.
There is a need, therefore, for reducing compounds, especially tin hydride compounds, which are both effective in reduction reactions and easy to separate from reaction mixtures after use.